The benefits of using dental floss for removal of plaque from teeth have been known for many years. Daily flossing is recommended by almost all dentists. Nevertheless, because of the difficulty and inconvenience involved in manipulating the floss and the time delay of several minutes that is involved, very few people actually use dental floss on a daily basis.
Because of the difficulty of access to the back teeth, proper flossing is not an easy accomplishment. Initially the floss must be positioned in the space between two adjacent teeth. This positioning requires passing the floss through a narrow contact region between the teeth which is typically 0.25 to 1.25 millimeters deep. As the floss passes through this contact region, it encounters considerable resistance and must be drawn tight in order to provide sufficient force for passage through the contact region.
The intertooth space beneath the contact region is filled with a wedge shaped piece of soft tissue known as the gingival papilla. Care must be taken to assure that the floss does not suddenly "snap" through the contact region between the teeth while under tension and damage the gingival papilla between the teeth. Frequently bleeding of the gingival tissue is induced by traumatic contact with the floss as the floss snaps through the contact region.
To prevent this gingival damage the force on the dental floss must be reduced substantially just as the floss passes beneath the contact. This requires considerable dexterity and control. Once the floss is positioned beneath the contact, it should be allowed to partially wrap around the tooth to about 100 degrees of arc. It can then be passed between the papilla and one of the teeth as flossing proceeds.
Next the floss is moved to the adjacent tooth, still within the gap. The floss is now wrapped about the adjacent tooth and the flossing process is repeated before the floss is withdrawn from the intertooth gap. At this point the tension on the floss must again be increased as the floss is forced back through the contact region and out of the intertooth gap.
Studies have shown that the dental floss can transport bacteria from one quadrant of the mouth to another. In addition, waxed dental floss is frequently used to facilitate the flossing operation. The wax neither helps nor hinders the actual flossing operation, but does provide lubrication to make it easier to pass the floss through the contact region. However, the wax tends to come off the floss after two or three teeth have been flossed. It is therefore desirable to be able to store a supply of floss in the floss holder and advance a new length of floss to an active section at frequent intervals. At a minimum, the floss should be advanced for each different quadrant of the mouth.
Because floss is most conveniently available in standard 200 yard spools or reels, it is desirable that the floss holder be able to accommodate such a spool. It is further desirable that the floss holder provide storage for used floss. This enables the user to delay final disposal of the used floss to a time that is most convenient to the user.
One of the problems associated with flossing is the time required each day for proper flossing. However, this time requirement would be no problem if the flossing could be done while a person is engaged in some other confining activity, such as driving an automobile. This would of course require a holder that could be controlled with one hand to provide proper manipulation and tensioning as well as advancement of the floss from a supply spool to a take up mechanism.
Several different floss holder devices have been developed to assist in the flossing operation. However, none of these are able to satisfy all of the requirements of an ideal floss holder. For example, U.S. Pat. No. 1,110,680 to Gamble teaches a "scissor" type of floss holder. The holder provides looped type handles that are difficult to hold and do not facilitate proper control of floss position and tension. Two hands are required to advance the floss and there is no storage for used floss. The new floss supply mechanism cannot accommodate a standard 200 yard supply spool.
U.S. Pat. No. 4,192,330 to Johnson teaches a principle embodiment that uses a fixed cartridge. Once the cartridge is inserted, the floss is locked in tension without convenient adjustment. The cartridge must be replaced to obtain a new length of floss. Several such replacements would not be practical during a single flossing operation. In an alternative arrangement, a fixed length loop of floss is attached to the holder and then subjected to constant tension. The tension cannot be adjusted as appropriate for a proper flossing operation.
U.S. Pat. No. 3,792,706 to Keese discloses a holder in which a length of floss is secured to the ends thereof. In one embodiment the ends may be manipulated in response to finger pressure in order to change the tension. However, the control leverage arm is too short to provide adequate control over tension. In an alternative embodiment the holder arms can flex, but this cannot provide adequate control over floss tension.
U.S. Pat. No. 3,906,963 to Jenkins et al. teaches an arrangement in which a thumb screw can control the spacing between holder arms. Such a screw is too slow and inconvenient to represent a practical tooth by tooth adjustment. The floss is maintained under constant tension by a spring. No quick, convenient manual control of floss tension is provided.
U.S. Pat. No. 4,151,851 to Bragg teaches a holder having supply and take up reels on opposite sides thereof. The holder does not allow immediate manual control over floss tension and a long narrow handle makes precise positioning and control of the holder difficult.
U.S. Pat. No. 4,214,598 to Lee discloses supply and take up reels on a nonadjustable holder.
U.S. Pat. Des. 251,075 to Schiff and U.S. Pat. Des. 251,074 to Schiff show floss holders which use a fixed length of floss that cannot be advanced. The holder would appear to provide limited control over floss tension.